Multiple section door construction



April 2, 1949. G. aRoer-zrzs 2,466,913

MULTIPLE SECTION DOOR CONSTRUCTION Filed June 25, 1945 5 Sheets-Sheet 1000,5 ops/w/va IN V EN TOR.

Gael 3.1209815 ATIDRAEY April 12, 1949. G. 5. ROGERS MULTIPLE SECTIONDOOR CONSTRUCTION 5 Sheets-Sheet 2 Filed June 26, 1945 INVENTOR.

Gel/ab 8 .Bogers W ATIOBNEY April 12, 1949. G. 5. ROGERS MULTIPLESECTION DOOR CONSTRUCTION Filed June 26, 1945 N W MN v S 3 w h w m w\@\0% l a. A m@ m MW W Jig & w. .m h v 21 9 MN April 12, 1949. G. 5. ROGERSMULTIPLE SECTION DOOR CONSTRUCTION 5 Sheets-Sheet 4 "'"ili Filed June26,, 1945 INVENTOR. Gael 5. Rogers BY ATTORNEY April 2, 1949. G. s.ROGERS 2,466;9l3

MULTIPLE SECTION DOOR CONSTRUCTION Filed June 26,, 1945 5 Sheets-Sheet 5Will.

65 Gael 8. Rogers ATTORNEY iatented Apr. 12, 1949 our re p stares ATEENi one we MULTIPLE SECTION DOORCONSTRUCTION Gael S. .Rogers, L'os.Angeles, "Ca-lit, lassignor to Kimball Elevator Company, rIjttL, iIiUS:Angeles,

Calif., a corporation of Califonnia Application June 26, 1945QSB1i3l No.601,669

Claims. 1

I This application relates to multiple section "door constructions inwhich a plurality of smaller-sectio-ns or door-elements are employed toclose a relatively large opening by arranging the door sectionsfor-movement in separate paths from a nested association such "as toexpose the door opening, to a relatively extended -butoverlappingassociation such asto close the door opening.

-More particularly, the construction or this 'invention contemplates the"provision of a plural door assembly in which each of the individualdoor elements making upthe p'luralityis adapted for movement relativebothto the door opening and "to the other door elements of theplurality, themovement of such door-elements-being effect- -ed by adirect'drive oi one of1such elements and an indirect drive of the otherelements being obtained by cooperative interengagement or the elements,whereby the motion directly imparted to such one element-is indirectlyapplied to such '17i0l1 of such adjacent door element to the speed ofmovement of suchmovingdoor element.

In multiple *section .door constructions of the :type with which thepresent invention is concerned, considerable difficulty is encounteredin the operation of the individual door vsections as a result of thenecessarily massive construction and the necessity for securing ratherrapid operation. Where such structures are employedjf or aircrafthangars and the like, or comparable structures in'which a relativelylarge spanis required in the full open position of the door, the

movement of the door into closing position or :.opening position shouldbe relatively rapid, and where a construction is employed in which therespective elements of the door structure are interengaged with oneanother. to secure the desired movement, the impact of a moving doorsection orgroup of door sections upon an adjacent doorsectionto-pick itup to the speed of the moving element is .de'leteriously high in manyinstances. "This is particularly true where material-such as sand,gravel,=small stones or the like *is iike'ly to accumulate up on thesupporting tracks on which the door sections ride in their movement,inasmuch as this condition results in a rather important resistance to'-be overcome by the door which is being set in motion, andthe momentumof the moving door section has to be absorbedby thead'j acen'tdoorasiitis-acceleratecl to the :speed 'of the =moVing-door section.

For the :albove reasons, Fit has heretoiore been considered'impraotioable'to employ multiple door structures of 'the pick-up type,-'-i. e.,- door strucztures wherein the moving *eiiort is applied to butone door section of #the multiple structure and the movement of theadjacent door sections "obtained upon engagement joy suchone-door-section, wherever the construction requirements call *forrelatively heavy or large door-sections. instead, the art hasconsistently called 'for installation s inwl'iich all of the doorsections are driven con- --cu-rrently, at differential speeds, wherefore"the multiple door structure is movedas a unit into and out of door open position. This requires rather 'large or poweriul "drive -rrna ans,inasmuch as each of the sections of the door structuretmust beaccelerated, 'i. p e., the :mass Ldf theentire .door structure has'to'be acted upon "by the 'drive n'ieans at'once, albeit part isaccelerated at a lesser rate than another part.

According'to the present invention, apick up type of multiple doorconstruction is provided which *issubiect to operation at a reducedpovver requirement {as compared to the power reguirement of doorjconstru'ctions of comparable size andvveight whichv provide forconcurrentroperation of the several door sections -constitutingLth'emultiple structure and is characterized by ithe absence of excessiveimpact .loads in operation.

Ibis a further particular object of this Linven- 'tion'toprovideayielding driving connection between adjacentdoor sectionsinamultipleesection structure of 'the ipi'ck-up type so'thatas afmovingdoor reaches astanding door sectionfthe momentum oi'themoving door visgradually imposed upon thisstanding door to accelerate fit to the speedof the moving portionsvof the structure without undue shock on. thestructure as a whole.

A particular object of the invention is, to providea hydraulic structureadapted to be setfinto operation when adjacent door sections ,are brqiglfit'into'interengaging relation, to reducethe force applied to a doorsection to hemovedlby a moving -.do0r section and distribute theapplication of suc'hiorce, over as'ignificant itimeinterval, whereby thedesired acceleration of the door to be moved is attained in thesubstantial absence of detrimental shock from impact.

The construction of the present invention may comprise, substantially, aplurality of door sections arranged in position to move in substantiallyparallel paths from a nested association in which they overlap eachother and establish an open condition for the door opening, and arelatively extended and preferably partially overlapping position inwhich they are offset in the direction of movement into a positionclosing the door opening, one of said sections being provided with meansdefining a bearing surface, and a door section adjacent said one sectionbeing provided with a portion defining a bearing surface in position toengage the first-named bearing surface and move the one door sectionupon movement of said adjacent door section in one direction, and one ofsaid door sections being provided with cushioning means yieldinglysupporting the associated bearing surface to permit limited motion ofsuch bearing surface relative to this one section upon such engagement,while resisting such motion, whereby the movement of the moving sectionin said direction causes gradual acceleration of the other section.

A further object of the invention is to provide a pick-up type ofmultiple door construction provided with cushioning means adapted to becaused to function upon interengagement of a moving door section with anadjacent less-rapidly moving section, in which the cushioning means isadapted to cause the interengaging door sections to establish a givenrelative positional relationship independent of the operating forcesimposed upon such door sections.

A further object of the invention is to provide a multiple structuredoor asembly of the pickup type provided with resilient yieldingcushioning means interposed between adjacent door sections which areadapted for interengagement for the purpose of imposing a moving efiortupon an adjacent door section by a given moving door section, in whichthe resilient yielding means is adapted to resiliently cushion theimpact of said moving door section upon such adjacent door section anddistribute the accelerating eiTort of such moving door section upon suchadjacent door section over a period of time controlled by a givenrelative movement between such door sections, said resilient yieldingcushionin means being adapted to establish such given relative movementin such manner that such given relative movement is caused to take placeindependent of the operating load existing at the position ofinterengagement of said door sections.

Other objects and features of this invention will be brought out in, orwill be apparent from, the following description of certain preferredembodiments of the invention as illustrated in the accompanyingdrawings, in which:

Fig. 1 is a front elevation, partly broken away, showing a plurality ofdoor sections in relatively extended position to close a door opening;

Fig. 2 is a partly broken away plan view thereof, looking down upon theplurality of door sections arranged in the relative position shown inFig. 1;

Fig. 3 is a horizontal section showing an assembly of three doorsections and illustrating the relative positions of the door sections inmovement thereof to expose the door opening, wherein the outermost doorsection has engaged and moved an intermediate door section into positionwhere it is just about ready to engage the last door section of thegroup to move it and thus expose the entire door opening;

Fig. 4 is a partly sectional elevation as taken on line l4 of Fig. 3;

5 Fig. ia is a partly broken end elevation as taken on line la- M inFig. 3;

Fig. 5 illustrates the operation of the yielding cushioning means as anouter door section is brought into engagement with an adjacent doorsection in movement of the door sections to a relatively extendedposition such as to close the door opening;

Fig. 6 is a longitudinal section through the form of cushioning meansshown in Figs. 1

through 5, embodying a hydraulic cushioning member;

Fig. 7 is a longitudinal sectional detail of the structure shown in Fig.6, as taken on line '!---'I therein and as shown by co-related line 1-1in Fig. 8 is a transverse section as taken on line 8-8 in Fig.7;

Fig. 9 is an enlarged sectional detail as taken on line 99 in Fig. 7

Fig. 10 is a view corresponding to Fig. 6, showing a modified embodimentof the invention;

Fig. 1?. is a transverse sectional view as taken on line iii l in Fig.10;

Fig. 12 is a transverse sectional view as taken on line i2l2 in Fig. 10;

Fig. 13 is a longitudinal sectional view as taken on line l3-i3 in Fig.10;

Fig. 14 is a view corresponding generally to Fig. 4, showing a modifiedform of fluid-displacement type of cushioning means, provided with meansfor causing a resilient operation of the structure;

Fig. 15 is a view corresponding generally to Fig. 4, showing a yieldingcushioning means adapted for operation in but one direction of forceapplication, with automatic means for returning the device to operativeposition after operation in said one direction; and

Figs. 16 and 17 show Varied arrangements of 4:; cushioning means whichmay be established according to this invention, depending upon thecharacter of the cushionin means provided.

Referring to Figs. 1 through 9 of the drawings, I have illustrated thearrangement of a 5.) plurality of door sections adjacent the dooropening associated with a building wall in Figs. 1 and 2, while in Figs.3 through 9 I have illustrated certain details of construction which maybe incorporated in the structure shown in Figs.

1 and 2. Referrin more particularly to Figs. 1

and 2, a portion of the building wall is indicated at l, at one side ofwhich a door opening 2 is provided. This door opening may extend fromthe wall portion l to the mid-point of the complete door opening ininstallations where the door opens at the center and the door sectionsare moved respectively to each side of the center to full open positionof the doorway, or it may be considered that the door opening shown at 2represents the full size of the opening.

A plurality of door sections 3a, 3b and 3c are provided for thisparticular installation, it being appreciated that substantially anydesired plural number of door sections may be provided, de-

pending upon the size of the installation involved. lhe door sectionsare adapted for translatory movement, preferably in substantiallyparallel paths and for this purpose may be supported on suitable flangedwheels 4 riding on separate sets of tracks or rails as shown at 511, 5band 50 for 'theirespectivefdoor sections. Inithe ordinary case thesemails will i be iplaced with their upper sur- @9385 in line with theplane of the floor of the building, wherefore wheeled trafficin-and outof the'tbuilding will be unimpeded. The upper edges of the door sectionsta-tc may besupported by a guide rail assembly shown generally at t,accordingito conventional practice.

iSuitable IJOWGI means are preferably provided ifOI"ICa11SlIlg thedesired movement of the .door sections between door-open and door-closedpositions, :and such power means may be provided through a driving chaindisposed :on suitable sprocket :8 in'the overhead structure of the door,saidt'chaina'ibeingadapted'to engage an operating bracket wring-s :uponthe door section which is eaused'ito :haverthe greatest movement, whichin this 'ca'se is:door section 60. A suitable driving element maybeattached .to one of the sprockets 8, suchaas-anelectrie motor iii,connectin with the adjacent-sprocketpreferably through suitablespeed-reducing means, not shown.

"Itwillwbe .appreciated that :it is not essential that rthe'doorsections be power driven, in spite .of the fact that in large structuresthe power driven arrangement is by far the most useful, inasmuch i-asthe features 'of this invention are quite'usef-ul where the doors arehand-operated orc'operatedby a removable or temporary power a-means suchas a tractor or truck. The accom panyingaclaimszfor this-reason, are notspecificallyrlimited to the provision of power operating means for theplural sections.

In :the ensuing description, Where the expression zout-er doorisectionis used, it will be understoodto refer to the door section which has thegreatest-movement, i. e., the door section 30 in the specificillustrations in Figs. 1 and 2, and where the expression inner doorsection. is used it will refer to the door section having the leastmovementyi. e., the doorsection 3a of Figs. 1 and 2. ,Theremaining doorsection 3b will be termed an -intermediate door section, with theunderstanding that there may be any desired number of'such intermediate'doorsections, or such inter mediate-sectionmaybe omitted, in any givenconstnuction.

rIt will Lbe comprehended also, that the door section which is innermostwith respect to the door opening itself -(i. e.,-in the plane of doorsection 3a) may actually constitute the door sec- .tion is required tomove .130 the greatest distance, Wherefore the expressions inner andouter door sections will be taken as referring mainly to the :physicallayout of the structure shown specifically in Figs. "1 and 2, ratherthan toaa limitation that eitherthe inner or .the outer door/section isthe one which requires the greatest movement.

iIni-my specific showing, the door section 3c is the ,:operating doormember for the plurality of door sections, i. e., is the door sectionwhich is drivenqdirectly by the driving means 1,13, :Q'and hand-in turnacts to operate the adjacent door sections -3b and 3a, and the doorsections ta-and 3b=are provided with brackets H which serve to causermovement ofthe door sections in the righthand-direction in Figs. 3through 5, hereinafter termed closing bracket, and bracket RE! which maybe termed opening? bracket. The closing and openin brackets of section3b are disposed imposition tobe operatedupon by the door section:-3c,and-similarly, the opening and closing brackets-H and 2 of section-3aare'disposed in position to be operated-upon by-tth'e door section .orupright t5, and carrying alm'o'va'ble c-ylinder M5 provided with anactuating foot member it?! positioned 'to engage the respective bracketsi l audit? of the next adjacentidoor section. Within theimovablecylinder it I providea piston-memher :i 8, said :piston member being:caused ito perr sist in :fixed positionwithirespect'to'lthe frame "#5of theadoorrsection:an'd the :theretozattached fixed support sleeve M.Thisipositioningof the member 'i 3 with respect to the fixed supportsleeve M may be obtained through the agency of cross arms 59 disposed insuitable Lnotches 52b in the piston +8 and extending :through elongatedslot 25 ein lthesmovable icylinder "it and through "coacting'ly shapedslots 122 in the ifi-Xed support sleeve M, the cross .arm t9 beingclamped-about the-center section :lta of :the piston member lit throughthe agency of :suitable bolts 23 or the like. A suitable "communicatingpassageiis providedto connect :the compression spaces or cy]-inders-ZLIA andfl' iBeat the respective ends or the movable cylindermember l 6, and I .may 'for this purpose provide the piston member "$8with an axial bore 2t. Suitable :c'omposition or leather cups 525a and@2517 are provided :at the respectiveends oithe piston member 18, a 'nut'25" be"i-ng provided to hold theicup ieath'er :at the lefthand'of thepiston *i 8.

At one end .of :the piston member l8,-such as the right-hand end in ithefigures of drawings, ii haveprovided asuitable formof metering orflowcontroiling means to limitrthe fluid displacement .between cylinderspaces 24A and 24B at the respective ends of the cylinder 1-6 throughthe pas-'- sage'zd. [Such a metering means may comprise a metering screw21B threadedly disposed in the cylinder-member t8 at the positiono'f thepassage .24 and provided with a bore-or passage'fidbommunicating with"the bore "24; the screw "26 may further be provided with a flat 2'!which 'isinclined with respect to the axis of the screw '26 so that uponadjustment of the screw along its length a greaterorilesser opening isprovided at the position of flat 21, and thus augment the fluid flowthrough bore 24"to various degrees. A key slot i'ZB may be'provided' inthe metering screw 2-6 andthe nut-Edwhich is adaptedto-hold apistonleather a25bat'the right-hand end o'f the piston l'8may1be,,providedwithan opening'SOso-that access to theikeysslot may be had through theopen end .of the cylinder member It by means of a screw driver or thelike. A removable plug "31 is provided'in the right-hand end of thecylinder 86, with-asmaller plug32 to provide access to the meteringscrew and 'to facilitate filling the system with suitable fluid. Thisfluid may comprise a compressible medium such as a gas or air, or anincompressible medium such as oil or other suitable liquid.

The operation of the construction is as follows:

Assuming the doors to be in the position shown in full lines in Figs.1'and.2, whenthemotor 1 0 is energized the door .30 will move to the-left. The actuating :foot -11 vassociated with the cushioningpmeans11-3 .011 the doorsection '30 will-be in :fully extended ,position(corresponding to the '2 position shown for the corresponding member onthe section 3b in Fig. 3), and when the left hand bearing surface ofmember I'I contacts the bracket I2 of the door section 3b the movablecylinder member I6 will be moved toward the right relative to the fixedsupport I4 attached to the door section 30, causing the volume ofhydraulic fluid in the cylinder space 24A at the left-hand side of thepiston member I8 to be reduced. This causes the fluid to pass toward theright through passage 24 into the cylinder space 24B, the rate of flowof the hydraulic fluid being controlled by the setting of the meteringscrew 26. This results in movement of the movable cylinder member Itrelative to the door section to which it is attached, and the forceexerted by the actuating foot I! upon the adjacent bracket I2 with whichit is in engagement Will be less than the full impact force of thesection 30; this force may be adjusted by properly adjusting themetering screw 26 so as to impose upon the adjacent door section 31) anaccelerating force suiilcient to bring it up to the speed of the morerapidly traveling section 30 at about the time the foot I! reaches itsfully inward position as shown in Fig. 3. It will be appreciated thatthe flow of fluid through the passages 24 and 24' may be established bya fixed, predetermined orifice or flow-limiting structure, rather thanan adjustable structure as specifically illustrated, without departingfrom the spirit of my invention. In any case, when the fully inwardposition of the movable cylinder member I8 is reached with respect tothe fixed piston member I8, section 3b is carried to the left along withsection 30 until the foot I! associated with the cushioning means on thesection 3b is brought into engagement with bracket I 2 associated withsection 3a, whereupon the accelerating operation on the section 3a isaccomplished in the same manner as described above in connection with31). When the three door sections 3a, 3b and 3c are brought near to theposition shown in dot-dash lines at the lower left-hand corner of Fig.2, i. e., when the doors are nearly fully removed from covering relationwith respect to the door opening 2, the motor I may be tie-energized orcaused to operate at a reduced speed so as to complete the movement ofthe doors at the proper position, as will be apparent to those skilledin the art. Where a reduced speed operation of the door section 30 iseffected, it is. preferable to establish a governed rate of decelerationof the driven door section which is somewhat less than the freedeceleration rate of the door sections 3b and 3a, so that the sections3a and 31) will not over-run section 30,

and during the final movement toward full dooropen position the sectionwill exert a reduced driving action upon sections 32) and 3a.

It will be appreciated that a given relative movement of the doorsections after interengagement of the actuating foot member I! of thecushioning means with the. opening bracket I2 is established by theallowable stroke of the cylinder It with respect to the fixed pistonmember I3. The acceleration of a picked-up door section will ordinarily(dependent upon the setting of the metering screw 26) have beencompleted by the time the full stroke (the given limited movement of theadjacent door sections) of the cylinder It has been effected. If theacceleration has been effected before the stroke is completed, the forceupon the foot member I I will be reduced to that required to keep thepicked-up door in motion, but any force sufiicient to overcome thefrictional drag of the member I6 will n at result in further movement ofthe member I6 relative to the member I8, until the full stroke isefiected, inasmuch a fluid displacement will take place through thepassage 24 under any pressure differential existing between spaces 24Aand 243. The cushioning means I3 thus serves to establish a controlledrelative movement of adjacent door sections after operativeinterengagement, under any operating load or stres existing between theinterengaging bearing surfaces, as defined by the foot member H and theadjacent bracket I2. Furthermore, after this given relative movement hasbeen effected, and the door sections thus brought into the desiredalinement with each other (as defined by the position of the brackets)there is no tendency for the door sections to be displaced from thisdesired condition of alinement as a result of the action of thecushioning means. This latter result is inherent in the operation of thecushioning means, which is adapted to produce the desired force opposingthe force produced by engagement of the adjacent door sections, withoutproducing a restoring force sunicient to effect a reverse relativemotion of the door sections upon completion of the abovementioned givenrelative movement.

When the doors have been moved to dooropen position, the cylinders I6will be fully retracted within the fixed support sleeve I4,corresponding to the position of the cushioning means shown in thesection 30 in Fig. 3, and when the desired closing operation isinstituted the section 30 will be moved to the right relative to section32) until the right-hand edge or bearing surface of the actuating footmember I1 is brought into engagement with the left-hand edge of theclosing bracket I I on the adjacent section 3b, following which thecylinder member will be withdrawn from the fixed support sleeve I4 ofthe cushioning means attached to the section 30 after the mannerindicated in Fig. 5 until the cylinder member I6 is completely withdrawnto its maximum left-hand position with respect to the support sleeve. Atthis time the section 31) will be fully accelerated to the speed of themoving door section 30 and will be carried toward the right until theactuating foot member I? of the cushioning means associated with thesection 3b is brought into engagement with the closing bracket IIprovided for the door section Set. It will be appreciated that asuitable cross member or reinforcing means may be provided at theposition of the bracket II, as indicated at Ila in Fig. 4, to suitablyreinforce the bracket II to withstand the accelerating forces imposed bythe cushioning means.

When the power driven ection 30 has been extended near its pnoperright-hand position at the extreme right of the door opening 2, thepower drive provided by the motor ID will be discontinued, as describedin connection with the opening movement of the doors above.

lhe form of the invention illustrated in Figs. 10 through 13 is adaptedto impose a frictional drag type of cushioning between adjacent doorsections instead of the hydraulic displacement type of cushioningprovided by the form of the invention shown in Figs, 3 through 9, andmay comprise an actuating foot member 33 mounted on a slidable drag bar3 5 having a forward portion 34a, 2. flat intermediate portion 34badapted to be engaged by a pair of opposed friction shoe members 35 eachprovided with a. friction layer 36 and pressed against the flat 34bthrough the agency of springs 31 backed up by an adjusting screwconstruction; as" shown at; 38.: mounted; on a crossbar ascconnected: tothe:supportingrframe. 40

which-.dsmountedron. thedoor. section-., The mem ber: 34? isprovided.with. a; rearward extension 4| journaled as at 52 on the rearward wallof the supporting: frame 40;. and; the-supporting frame may furtherbeprovided with, a mounting flange 45: adapted. to. be attached to theupright 44; of:

the door:- frame in any suitable manner, as: through the; agency ofboltsor the like. A; removable: journal member 45. is; provided for theforward; extended portion- 3.411: of" the; member 34,. together.- withalock-nut. 35, mounted; in; a suitable threaded opening in the mountingflange 4'3: and: serving to guide the. forwardly extending: portion 36a"of. the,- drag bar. In order to provide for removal of the drag barfrom. the. supporting frame 40, I. may provide a rectangular openinglmat right angles to the normal position of the intermediate flatportion 34b of the drag bar at; of. sufficient size: to; permitwithdrawal of the. drag. bar from the doorassembly upon removal of: the:friction shoe members, springs,

et: cetera,. and rotation of: the drag bar through.

90?; In. Fig. 1.1.. I. have shown: in dot-dash lines the positionofthe.- drag. bar portion 34b in. operation. A bracket. member 4:!correspondingin: function to. the'bracket member [2; above, may beprovided; for the intermediate door section upon: whichathe; actuatingfoot member 33 of: a cushioning means on the; next adjacent sectionwillimpinge in operation. The operationv of this type of apparatus is:entirely comparable to that shownat I3. in. the first described form ofinvention, having. in; mind that the resistance movement results from.the frictional drag of the member id-b upon the friction shoes 35instead of the hydraulic flow or fluid displacement as provided in thefirst form: of: the invention.

Referringtd Fig. 14:.1 have illustrated a form of fluid-displacementcushioning means which. is adapted to provide a. resilient resistance toimpact upon interengagement of twoadiacent doorsections. This form of.device may correspond generally to; the form shown. at it, above,including afixed. support sleeve M mounted upon an upright [5 of a doorframe, andcarrying a movable cylinder member It provided with anactuating foot member ll, all as corresponding to: parts t t-l1- of thefirst-described form. of cushioning means. Within the cylinder mem her.It! I may provide a fixed piston assembly corresponding. to that shownat. it, above, complete: with an. axial passage 2t and. metering means2.62-ls. The piston member it is fixed against movement with IBSPECtitOlZhQ door frame portion [5 as through cross arms t9 intersecnred:through bolts 23', as above.

The-desired; resilient action is secured. through the agency of, apairof pressure surge chambers 5. and-152', mounted on the rearwardlyprojecting portion 53; of: the cylinder member it. for ex ample. andrespectively connected tothe posi tion of the compression spaces and MBthrough external passages 54 and 55. Suitable filling plugs 56 and 5-lmaybe provided for the chambers 5| and 5 2.

The operation of this form ofdevice is such that when the door sectioncarrying the portion [5! ismoved to the left, and the actuating footmember FF is brought into engagement. with a. bracket 12" on an adjacentdoor. section, the pressurev built u in the compression space at theforward end of the cylinder it (251A) will cause fluid flow throughaxial passage 2 in the piston member !8.-. as1in. the; prior easel. butin addition will force fluid" upwardly in: the surge chamber5l,,buildingup the pressure: in the air space 5!" in the chamber 5!.The-1am space serves as a resilient: cushion, permitting, displacementof the cylinder member 16 inde-- pendent. of the fluid. displacementthrough the passage 24. When the actuating. force upon the cylinder I5is reduced, the pressure inspaoeblr" will tend to equalize by forcing.liquid back-into the space 24A, thence into space 243; through; passage2s, thus allowing. the fullirelative move:- ment of the door sections;to take place. as,- limited by the stroke, of member. I61. Operation ofthe device in the opposite, direction,v causing: compression in the airspace 5.2. of the chamber; 52 should readily be; apparent.

It will be seen that-theform of:Fig...14iprovides=; for displacement of:a relatively incompressible fluid such asa hydraulic, oil; or. otherliquid, and a compressible fluid. such, as air; or other gas within thesurge chambersv 5,1. and 52;. Adiust ment: orvariation of? theyresilient forces. in the system may be accomplished: by'fillingthechambers; 5.! and 5.2: to varied; heights; thus; altering the volume.of the air spaces, 5!? and: 521'- ItzWi'Hl further be appreciated that atype of:- operation: comparable to. that provided. bythefor-m of Fi'g;14- may be, had with. the form of: device shown: at: lril in Figs.v 3-9,by incompletely filling: the de vice with incompressible fluid,providing a; partiah air space forcompression to.establish aresili'entresistance to the. cylinder movement.

The several forms of device shown in. Figs; 3 through 14.. are adapted,tobeplacedl in positioni for providing a yielding resistance torelative; movement of: adjacent door sectionsin. onedirec tion, aftercompletion. of the yielding resistance in. the opposite direction,wherefore. the. device;

40 is. ready to operate; in. the opposite. direction to;

which it, has just operated, at. alt times.

In the fluid-displacement forms of:- cushioning means shown in Figs.3-9.- and; 1.4.; it: will. beap. preciated that the respective piston:ends. of. the piston member t8: operating. in; the compression; spaces24A. and 2413 actually constitute twosep'e arate fluid-displacementmembers which: are mechanically interconnected through the piston.member and hydraulically interconnectedi through; the. passage 2d...These separate. fluiddisplacement. membersare so mounted for con-.-ven-ience only; and' the functional: equivalence oi separate unitsmounted upon a. single door section, or separate units mounted onadjacent door sections will be apparentto: one familiarwith mechanicalprinciples.

As an example, I may provide a cushioning means of the fluiddisplacement: type which is adapted for operation. in: one directiononly; the return motion of the; device into operative posi -i tion readyfor a, fresh cushioning action. being obtained within the device itselfinstead; of through fluid displacement from a co-nelated cushioningmember; Such a structure is mus--- trated in Fig. 15, comprising acylinder member 60 rigidly mounted on one door section. and: providedwith a piston: GI, a piston rod' 62': and an actuating foot member 63adapted to engage. a properly positioned opening or closing bracket onan adjacent door section. A, spring 64; is; provided. within thecompression spans: 6d.- withim the cylinder to. of such strength; as tobias; the piston, at to. an: outward. position upon remoyal of forcevupon. the member 63.1 A; surge. chamber 65. is provided, mounted upon.the cylinder Bil;

if desired, in fiuid communication with the cylinder space The chamber55 may open to the atmosphere as at E2. A line ii! from the space Eli isconnected through passage 68 to a flow control valve 69 and thencethrough passage it to the bottom of chamber 65, and for more rapidreturn circulation of the fluid I may provide a by-pass line H having acheck valve 12 and connecting between passages "iii and El.

The device of Fig. 15, as so far described, wiil operate to provide ayielding resistance to movement of the member 53 in a right-handdirection, under a metering action comparable to that obtained by themember 93, and upon removal. of the moving force, the spring 8 willreturn the piston 5! to normal operating position. If desired, theresilient feature of the form shown in Fig. 14 may be incorporated inthe device of Fig. 15, by providing a branch line is provided with avalve '15 and communicatingfrom the passage 53'! to a pressure surgechamber it cor responding to one of the chambers 52 or 532 above.

It will further be appreciated that the arrangement of the cushioningmeans through which interengagement of adjacent door sections isprovided is subject to considerable variation. In Figs. 3 through 9, and14, a single, double-acting cushioning means is provided, whichobviously may be established upon either one of a pair of door sections.In Fig. 16 I have illustrated two door sections 80 and 8i, the section89 being provided with a cushioning means 82 which may be of the typeshown in Fig. 15, i. e., adapted to function in but one direction. InFig. 17 I have shown two door sections 83 and 84, the section 84 beingprovided with two cushioning means 85 and 86, each of which may be ofthe type of Fig. 15. The cushioning means 85 and 86 may be disposed oneupon each door section, if desired. Where operation after the manner ofthe form shown in Figs. 3-9, through 13, or 14 is desired, i. e., wherethe completion of the stroke of the cushioning means in one directionserves to place the device in position to operate upon relative movementof the door sections in the reverse direction, it is desirable to placeboth cushioning members 85 and 86 on the same door section, so that aconvenient interconnection (either mechanical or fluid, or both) may beestablished.

Other modifications will occur to those skilled in the the art, and Itherefore do not consider my invention to be limited to the specificdetails of construction herein set forth and shown in the accompanyingdrawings, but rather to the scope of the subjoined claims.

I claim:

1. A plural door construction for a door opening, which comprises: twodoor sections adapted for movement in substantially parallel pathsbetween a door-open position in which the door sections are disposed inan overlapping nested association and a door-closed position in whichthe door sections are disposed in a relatively extended association; andinterengaging means including cushioning means associated with said doorsections and adapted to establish a yielding interengagement betweensaid door sections upon movement of one of said door sections in onedirection, and operable upon such interengagement to graduallyaccelerate and move the other door section in the direction of movementof said one door section.

2. A plural door construction for a door opening, which comprises: twodoor sections adapted for movement in substantially parallel pathsbetween a door-open position in which the door sections are disposed inan overlapping nested association and a door-closed position in whichthe door sections are disposed in a relatively extended association,each of said door sections being provided with a bearing member, saidbearing members being engageable with each other upon movement of one ofsaid door sections in one direction; and cushioning means associatedwith one of said bearing members and yieldingly supporting the same,whereby said one bearing member is caused to undergo limited movementwith respect to the associated door section upon such engagement, saidcushioning means being adapted to resist said limited movement wherebysuch engagement results in a gradual acceleration of a door section by amoving door section.

3. A construction set forth in claim 2, said cushioning means comprisingfluid displacement means.

4. A construction as set forth in claim 2, said cushioning meanscomprising friction means.

5. A plural door construction for a door opening, which comprises: twodoor sections adapted for movement in substantially parallel pathsbetween a door-open position in which the door sections are disposed inan overlapping nested association and a door-closed position in whichthe door sections are disposed in a relatively extended association; andinterengaging means including cushioning means associated with said doorsections and adapted to establish a yielding interengagement betweensaid door sections upon movement of one of said door sections in eitherdirection, and operable upon such interengagement to graduallyaccelerate and move the other door section in the direction of movementof said one door section.

6. A construction as set forth in claim 5, said cushioning meanscomprising fluid displacement means.

7. A plural door construction for a door opening, which comprises: twodoor sections adapted for movement in substantially parallel pathsbetween a door-open position in which the door sections are disposed inan overlapping nested association and a door-closed position in whichthe door sections are disposed in a relatively ex-' tended association;means defining two bearing surfaces on each of said door sections; oneof the bearing surfaces of one of said door sections being adapted toengage with one of the bearing surfaces of the other door section uponmovement of one of said door sections in one direction and therebydefine a pair of interengaging surfaces, and the other bearing surfaceof said one door section being adapted to engage the other bearingsurface of said other door section upon movement of said one doorsection in the reverse direction and thereby define a second pair ofinterengaging surfaces, one bearing surface of each of said pairs beingmounted for movement relative to its associated door section; andcushioning means operatively associated with the movable bearingsurfaces of each of said pairs and adapted to establish a yieldinginterengagement between said door sections upon movement of said onedoor section in either direction, and operable upon such interengagementto gradually accelerate and move the other door section in the directionof movement of said one door section.

8. A construction as set forth in claim '7, said cushioning meanscomprising fluid displacement.

13 cushioning means comprising two separate cushioning means adapted tooperate independent of one another.

10. A construction as set forth in claim 7, said cushioning meanscomprising separate fluid displacement members in fluid communicationwith one another, and including metering means for controlling the rateof fluid displacement from one fluid displacement member to the other ineach direction of operation, to thereby establish a given yieldingcondition.

11. A plural door construction for a door opening, which comprises: twodoor sections adapted for movement in substantially parallel pathsbetween a door-open position in which the door sections are disposed inan overlapping nested association and a door-closed position in whichthe door sections are disposed in a relatively extended association; andinterengaging means including cushioning means associated with said doorsections and adapted to establish a yielding interengagement betweensaid door sections upon movement of one of said door sections in onedirection, and operable upon such interengagement to graduallyaccelerate and move the other door section in the direction of movementof said one door section, said cushioning means having a fixed portionmounted on one of said door sections and a movable portion positionedfor engagement by the other door section upon such movement of one ofsaid door sections, and movable relative to said fixed portion a limitedamount in response to force produced by said engagement, whereby a givenrelative movement of said door sections is produced following initialengagement thereof.

12. A structure as set forth in claim 11, said cushioning means beingadapted to produce a force in opposition to said first-named force andthereby resist such relative movement, in the absence of the productionof a restoring force sufficient to efiect relative motion of said doorsections opposite said given relative movement upon completion of saidgiven relative movement.

13. A plural door construction for a door opening, which comprises: twodoor sections adapted for movement in substantially parallel pathsbetween a door-open position in 'which the door sections are disposed inan overlapping nested association and a door-closed position in whichthe door sections are disposed in a relatively extended association; andinterengaging means including fluid-displacement type cushioning meansassociated with said door sections and adapted to establish a yieldinginterengagement between said door sections upon movement of one of saiddoor sections in either direction, and operable upon suchinterengagement to gradually accelerate and move the other door sectionin the direction of movement of said one door section, said fluiddisplacement type cushioning means being provided with a substantiallyincompressible fluid, and being adapted to cause a limited flow of suchfluid during such yielding interengagement.

14. A plural door construction for a door opening, which comprises: twodoor sections adapted for movement in substantially parallel pathsbetween a door-open position in which the door sections are disposed inan overlapping nested association and a door-closed position in whichthe door sections are disposed in a relatively extended association; andinterengaging means im cluding fluid-displacement type cushioning meansassociated with said door sections and adapted to establish a yieldinginterengagement between said door sections upon movement of one of saiddoor sections in either direction, and operable upon suchinterengagement to gradually accelerate and move the other door sectionin the direction of movement of said one door section, said fluiddisplacement type cushioning means being provided with a substantiallyincompressible fluid, and being adapted to cause a metered flow of suchfluid during such yielding interengagement, together with a compressiblefluid adapted to establish a resilient opposition to the impactresulting from such interengagement, said cushioning means beingprovided with means dissipating such resilient opposition upon 40completion of such metered flow.

GAEL S. ROGERS.

REFERENCES CITED The following references are of record in the flle ofthis patent:

UNITED STATES PATENTS

